状态机演示程序。开始时，开始按钮点亮，点击下一步，表示状态的布尔灯顺序点亮，点击下一步，按照状态三、二、一变化。-State machine demonstration program. Initially, the Start button is lit, click Next, indicate the state of the Boolean lights illuminate sequentially, click Next and follow the state three, two, one change.